Dermoscopic monitoring of melanocytic skin lesions: clinical outcome and patient compliance vary according to follow-up protocols.

BACKGROUND: Dermoscopic monitoring of melanocytic lesions increases the likelihood that featureless melanomas are not overlooked and minimizes the excision of benign lesions. Objective To examine clinical outcome and patient compliance using different follow-up protocols.

METHODS: A retrospective analysis of 600 lesions from 405 patients (aged 6-79 years) was performed to examine patient compliance and clinical outcome in patients with multiple atypical melanocytic lesions undergoing sequential dermoscopy imaging during short-, medium- or long-term follow-up. Based on the degree of dermoscopic atypical features, patients were scheduled for short-term monitoring with follow-up after 3 months, medium-term monitoring with follow-up after 6 months or long-term monitoring with annual follow-up. Criteria leading to excision of monitored lesions differed according to the follow-up protocol.

RESULTS: In a median follow-up period of 23 months, 54 (9%) lesions were excised, revealing 12 early melanomas (occurring in 3% of monitored patients), one basal cell carcinoma and 41 melanocytic naevi. The melanoma/benign ratio of excised lesions was 1 : 3.4. Seven of 12 melanomas showed changes after two to four visits, corresponding to 8-54 months of follow-up. Patient compliance was 84% for short-term monitoring, 63% for medium-term monitoring and 30% for long-term monitoring.

CONCLUSIONS: In patients with multiple naevi sequential dermoscopy imaging is a useful strategy to avoid missing melanomas while minimizing unnecessary excision of benign lesions. For better compliance, the first re-examination should be scheduled at 3 months after the baseline visit. Regular annual follow-up monitoring is also needed to detect slow-growing melanomas in which subtle changes may become apparent only over time.